Positive electrode material powder, positive electrode and lithium secondary battery including the same
Abstract
A positive electrode material powder including a lithium nickel-based oxide represented by Chemical Formula 1 (Li a Ni b Co c M 1 d M 2 e O 2 ) and having a degree of single-particle formation, represented by the following Equation (1), of 0.3 to 0.8: ∑ i = 1 n 4 π 3 R i 3 n × 1 D 50 . In Equation (1), R i is a radius of the i th grain as measured by subjecting an electrode manufactured using the positive electrode material powder to ion milling and then analyzing the cross section of the electrode by electron backscatter diffraction (EBSD), n is the total number of grains as measured by the EBSD analysis and ranges from 350 to 450, and D 50 is a volume-cumulative average particle diameter of the positive electrode material powder as measured using a laser diffraction particle size analyzer.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1 . A positive electrode material powder comprising a lithium nickel-based oxide represented by the following Chemical Formula 1, and having a degree of single-particle formation, represented by the following Equation (1), of 0.3 to 0.8:
Li a Ni b Co c M 1 d M 2 e O 2 [Chemical Formula 1]
in Chemical Formula 1, M 1 is Mn, Al, or a combination thereof, M 2 is one or more selected from the group consisting of Ba, Ca, Zr, Ti, Mg, Ta, Nb, and Mo, and 0.80≤a≤1.20, 0.55≤b<1, 0<c<0.45, 0<d<0.45, and 0≤e≤0.20 are satisfied;
Degree
of
single
‐
particle
formation
=
∑
i
=
1
n
4
π
3
R
i
3
n
×
1
D
50
Equation
(
1
)
in Equation (1), R i is a radius of an i th grain as measured by analyzing an electrode manufactured using the positive electrode material powder using electron backscatter diffraction (EBSD) after being subjected to ion milling,
n is a total number of grains as measured by the EBSD analysis and ranges from 350 to 450, and
D 50 is a volume-cumulative average particle diameter of the positive electrode material powder as measured using a particle size analyzer.
2 . The positive electrode material powder of claim 1 , wherein the positive electrode active material powder comprises at least one of a single particle consisting of one nodule and a pseudo-single particle which is a composite of 30 or less nodules.
3 . The positive electrode material powder of claim 1 , wherein the positive electrode material powder consists of a combination of positive electrode active material particles in the form of a single particle and in the form of a pseudo-single particle.
4 . The positive electrode material powder of claim 1 , wherein the positive electrode material powder has an average grain diameter of 0.5 μm to 4 μm.
5 . The positive electrode material powder of claim 1 , wherein the positive electrode material powder has a D 50 of 2.0 μm to 10.0 μm.
6 . The positive electrode material powder of claim 1 , wherein the nodules of the positive electrode material powder have an average particle diameter of 0.8 μm to 4.0 μm.
7 . The positive electrode material powder of claim 1 , wherein the positive electrode material powder has a degree of single-particle formation, represented by Equation (1), of 0.3 to 0.6.
8 . The positive electrode material powder of claim 1 , wherein, in the Chemical Formula 1, 0.80≤b<1, 0<c<0.20, 0<d<0.20, and 0≤e≤0.10 are satisfied.
9 . The positive electrode material powder of claim 1 , wherein the lithium nickel-based oxide is represented by the following Chemical Formula 1-1:
Li a1 Ni b1 Co c1 Mn d1 Al d2 M 2 e1 O 2 [Chemical Formula 1-1]
in Chemical Formula 1-1, M 2 is one or more selected from the group consisting of Ba, Ca, Zr, Ti, Mg, Ta, Nb, and Mo, and 0.80≤a1≤1.20, 0.82≤b1<1, 0<c1<0.18, 0<d1<0.18, 0≤d2<0.18, and 0≤e1≤0.20 are satisfied.
10 . The positive electrode material powder of claim 1 , wherein the positive electrode active material further includes a coating layer formed on the surface of the lithium nickel-based oxide and including one or more coating elements selected from the group consisting of Al, Ti, W, B, F, P, Mg, Ni, Co, Fe, Cr, V, Cu, Ca, Zn, Zr, Nb, Mo, Sr, Sb, Bi, Si, and S.
11 . A positive electrode comprising the positive electrode material powder according to claim 1 and a current collector.
12 . A lithium secondary battery comprising the positive electrode according to claim 11 and a negative electrode.Cited by (0)
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